Improving Abrasive Wear Resistance for Steel Hardox 400 by Electro-Spark Deposition

Resumo

The mechanical and tribological properties of the steel Hardox 400 after electro-spark deposition (ESD) using electrodes made of hard-alloy carbides T15K6 (79% WC + 15% TiC + 6% Co), WK6 (94% WC + 6% Co), and composite materials based on iron such as 12S2 (12% Ni + 2% Si + 15% Cr₃C₂ + 71% Fe), K4F (15% WK3 (97 WC + 3 Co) + 4% Cr₃C₂ + 1% V + 80% Fe), and tungsten disilicide WSi₂ (76.6% W; 23.4% Si) have been studied. The energy parameters (the energy of pulsed discharges, the amplitude and repetition rate thereof) and technological parameters (the type of processing electrode motion, vibration or vibration/rotation) for the ESD process, as well as the electrode composition at which the highest quality surface layers with high wear resistance is observed, have been optimized. The effect of the energy and technological parameters of the ESD process exerted on the properties of the coatings obtained has been determined. The studies have shown that coatings of WC–TiC–Co and WC–Co applied onto steel Hardox 400 exhibit a twofold decrease in abrasive wear. At the same time, it has been found that the wear resistance of composite coatings is sufficiently affected by the application modes (up to a 2.5-fold decrease in the wear level), and the coatings made of composites 12S2 and K4F are competitive with respect to coatings made of hard alloys based on tungsten carbides.